RecyclerView中的并发修改[重复]

Question

这个问题在这里已有答案：

• Iterating through a Collection, avoiding ConcurrentModificationException when removing objects in a loop 23回答

我在List从RecyclerView删除物品时遇到了问题。它包含已检查项目的列表。我想取消选中列表中的一项。

因此，方法removeGroupItem()从已检查项目列表中删除项目。这里是：

private void removeGroupItem(String groupId) {
    for (String group : pickedGroups) {
        if (group.equals(groupId))
            pickedGroups.remove(group);
    }
}

如果我在某个项目上快速点击2-3次 - 它会崩溃。这是stacktrace：

java.util.ConcurrentModificationException
        at java.util.ArrayList$Itr.next(ArrayList.java:860)
        at com.camness.vidimguploadjun2016.trips.group_adapter.GroupsAdapter.removeGroupItem(GroupsAdapter.java:76)
        at com.camness.vidimguploadjun2016.trips.group_adapter.GroupsAdapter.access$300(GroupsAdapter.java:16)
        at com.camness.vidimguploadjun2016.trips.group_adapter.GroupsAdapter$GroupViewHolder.lambda$new$0$GroupsAdapter$GroupViewHolder(GroupsAdapter.java:65)
        at com.camness.vidimguploadjun2016.trips.group_adapter.GroupsAdapter$GroupViewHolder$$Lambda$0.onClick(Unknown Source:2)
        at android.view.View.performClick(View.java:6303)
        at android.widget.CompoundButton.performClick(CompoundButton.java:134)
        at android.view.View$PerformClick.run(View.java:24828)
        at android.os.Handler.handleCallback(Handler.java:789)
        at android.os.Handler.dispatchMessage(Handler.java:98)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6798)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)

提前感谢大家的帮助。

Answer 1

首先要改变工作的逻辑。例如，您可以在删除后中断

    for (String group : pickedGroups) {
        if (group.equals(groupId)) {
            pickedGroups.remove(group);
            break;
        }
    }

但是您还必须同步有权访问此数组的线程。例如

    synchronized(pickedGroups) {
       for (String group : pickedGroups) {
           if (group.equals(groupId)) {
               pickedGroups.remove(group);
               break;
           }
       }
    }